Fructose and High Blood Pressure

If you have high blood pressure, your doctor has probably told you a dozen times to cut way back on salt (sodium). But this works only for people who have a "salt-sensitive phenotype," which results from both genetic makeup and environmental influences.

New preliminary research offers another strategy that might work for more of us. If we cut back on the fructose that we eat from added sugars, we may be able to control high blood pressure.

Most people with diabetes have high blood pressure, or to use the technical name, hypertension. High blood pressure is, after all, one of the key components of the metabolic syndrome, or syndrome x, that leads to diabetes.

When doctors talk about our blood pressure being high they mean a level of more than 120/80 mmHg. Those numbers are shorthand for a systolic or peak pressure of 120 and a diastolic or minimum pressure of 80 millimeters of mercury.

Measuring our blood pressure isn't as easy as our doctors and nurses pretend. Our blood pressure levels vary almost as much as our blood glucose levels do. All sorts of things can make our blood pressure appear higher than it actually is -- everything from "white-coat hypertension" and not sitting quietly for at least five minutes to the stress of having to pee, as I wrote here earlier.

But if your blood pressure is still high, you need to control it. Even moderately levels lead to shortened life expectancies.

A diet high in fructose increases the risk of developing high blood pressure, according to a paper presented October 29 at the American Society of Nephrology's 42nd Annual Meeting and Scientific Exposition in San Diego. The findings suggest that cutting back on processed foods and beverages that contain table sugar (sucrose) and high fructose corn syrup may help prevent hypertension.

Diana Jalal, MD, of the University of Colorado Denver Health Sciences Center and her colleagues studied this question in a large representative group of American adults. They examined 4,528 adults with no prior history of high blood pressure. They calculated their fructose intake based on dietary questionnaires, including foods such as fruit juices, soft drinks, bakery products, and candy.

Dr. Jalal's team found the median fructose intake was 74 grams of fructose per day, the equivalent of 2 and one-half sugary soft drinks. They accounted for a number of variables such as body mass index and waist circumference, salt intake, total kilocalorie ingested, and total carbohydrates ingested per day. People who ate or drank more than that amount of fructose had higher risks of hypertension. In fact, they had a 87 percent higher risk of a level higher than 160/100mmHg.

The preliminary announcement that the American Society of Nephrology sent me implied that Dr. Jalal and her team studied the consumption of only high fructose corn syrup and not of table sugar (sucrose). That concerned me, because table sugar is half fructose. It is is a disaccharide of glucose and fructose. So I asked Dr. Jalal if they studied the effect of table sugar too.

"We agree that the consumption of fructose over the last century has come from sources of food high in added sugar -- be it high fructose corn syrup or table sugar (sucrose)," she replied. "So, in our study we evaluated the intake of fructose from sources high in added sugar such as soft drinks, juices, bakery products such as cakes, doughnuts, and cookies, etc, in addition to chocolate, dairy desserts, candy, dried fruits, and honey, jam, sugar added to coffee or tea, and syrup. So, you can see that we did include sucrose."

Whether we get our fructose from high fructose corn syrup or from table sugar doesn't matter. Any form of added fructose spells trouble. Even through Dr. Jalal and her team's research is preliminary, it gives us one more reason to avoid fructose.